MDL judge rules on what evidence supports a gastroparesis claim

In August 2025, U.S. District Judge Karen S. Marston issued a 78-page decision in the federal GLP-1 multidistrict litigation (MDL 3094) addressing what medical proof plaintiffs must have to support a gastroparesis claim. The ruling followed more than 3,700 pages of briefing and evidentiary hearings ^[1].

The litigation, centralized in the Eastern District of Pennsylvania in February 2024, involves Novo Nordisk (Ozempic, Wegovy, Rybelsus, Victoza, Saxenda) and Eli Lilly (Mounjaro, Zepbound, Trulicity) ^[1]. Plaintiffs allege the companies failed to warn that delayed stomach emptying — a known mechanism of these drugs — could progress to severe, persistent gastroparesis, intestinal blockages and other complications ^[1].

What the ruling addressed

Early in the case, Judge Marston told the parties to focus on three "cross-cutting" issues that would shape the whole litigation: whether claims are preempted by federal law, whether plaintiffs must present specific diagnostic testing evidence, and whether there is enough general causation evidence linking GLP-1 medications to gastrointestinal injuries ^[2]. The August ruling resolved the diagnostic testing question; preemption and general causation were left for later ^[2].

Since then, the court has continued to require objective diagnostic testing for gastroparesis claims ^[1]. In practice, that points to a gastric emptying study, also called scintigraphy — a test in which a patient eats a meal containing a small amount of radioactive material while imaging tracks how fast food leaves the stomach. Per the National Institute of Diabetes and Digestive and Kidney Diseases, diagnosis typically requires more than 10% retention at four hours ^[1].

The full text and precise holdings of the 78-page opinion are not reproduced in the available sources, so exactly which categories of claims survived, and on what terms, is not spelled out here. One source describing the ruling is a litigation-tracking site carrying attorney advertising ^[1].

The numbers behind the litigation

As of September 2026, 4,022 cases were pending in MDL 3094, out of 4,056 filed — growth of about 202% since January 2025, when the count was 1,331 ^[1]. Roughly 75% of complaints allege gastroparesis or "stomach paralysis," 18% allege ileus, and 8% involve gallbladder injuries ^[1].

Much of the science debate traces to an October 2023 JAMA study by Sodhi and colleagues, which reported that people using GLP-1 drugs for weight loss had 3.67 times the risk of gastroparesis, 4.22 times the risk of bowel obstruction and 9.09 times the risk of pancreatitis compared with another weight-loss drug group ^[1].

Separately, regulators have moved. The FDA added an ileus warning in September 2023, a pulmonary aspiration warning about general anesthesia in January 2025, and in October 2025 updated the Ozempic label to say the drug "is not recommended in patients with severe gastroparesis" ^[1]. Vision-loss (NAION) claims were split into a separate MDL 3163 in December 2025, also before Judge Marston, with about 200 cases as of September 2026 ^[1][2].

Why it matters for patients

The ruling is a legal decision about evidence, not a medical finding about whether GLP-1 drugs cause gastroparesis. The court has not yet decided general causation — whether the science supports a link at all — or whether federal law preempts these claims ^[2].

For people who believe a GLP-1 medication caused lasting stomach problems, the practical effect is that documentation matters. A recorded diagnosis based on symptoms alone appears to carry less weight in this MDL than an objective gastric emptying study ^[1]. Whether a given person's records meet that standard is a question for a lawyer and their treating clinicians, not something this article can answer.

For patients simply weighing whether to start or continue treatment, nothing about the ruling changes the drugs' approved status. It does highlight that the labels now carry specific gastrointestinal language, including the October 2025 severe-gastroparesis statement ^[1].

What happens next

A December 16, 2025 case management order set the 2026 schedule: plaintiff expert reports by January 2, defense reports by February 12, plaintiff rebuttals by February 23, and expert depositions completed by April 10 ^[2]. Motions to exclude expert opinions were due April 28 and summary judgment motions April 30, with opposition briefs June 3 and June 16 and reply briefs June 24 and July 24 ^[2].

Summary judgment briefing continues through July 2026, with bellwether trial selection expected around mid-2026 and first trials possible in late 2026 ^[1]. No settlements had been announced as of September 2026 ^[1].